Prefabricated trusses are widely used in modern construction, and provide fast construction and strength and reliability in service. These trusses typically comprise upper and lower chord members forming the perimeter of the truss, and a plurality of web members between the chord members. Some of these web members are under tension, and some of these web members are under compression. The chord members and web members are usually made of wood, and joined with nailing plates, or they may be made of metal members and joined with hardware. Under certain loading conditions some of the web members that are under compressive loading in a truss may tend to bend or flex out of the plane of the truss. This bending or flexing weakens the truss, and can potentially lead to failure. Thus, it is common to brace the web members in a truss by tying the web members of adjacent trusses together. Ultimately the web members must be tied to a rigid structure, such as an end wall, or the effect of tying the web members together will simply be causing the tied web members to fail in unison. It is tedious and time consuming to properly tie the web members, and the failure to properly tie web members is a common cause of truss failure. Sometimes it is not possible to tie the web members together, for example where adjacent trusses have different configurations. In these cases the web members may be individually supported by securing stiffeners to the web members. On a wooden web member, for example, a section of lumber whose wider dimension is perpendicular to the wider dimension of the web member can be nailed to the web member. Because these stiffeners project out of the plane of the truss, they must be individually installed at the work site, otherwise the stiffeners would interfere with the handling of the trusses in which the stiffeners are incorporated. It is tedious and time consuming to install these stiffeners at the job site, and thus it is very expensive.